American Airlines cancels flights because it's just too hot to take off

A heatwave in the US has forced the cancellations of dozens of flights as soaring temperatures bring the worst heat the southwest has experienced in years.

Phoenix, Arizona, reached highs of 47C (116F) prompting American Airiines to cancel at least 43 flights in and out of the city.

The extreme temperatures pose problems for many planes as they cause changes in air density that make it harder to take off. Airlines have been grounding flights of smaller planes, while limiting the luggage, cargo and fuel, and limiting sales on larger jets to reduce the weight of the aircrafts.

(Ross D. Franklin/AP/PA)

American Airlines warned passengers over the weekend that many flights may be grounded during the heatwave and is allowing those flying between Monday and Wednesday to change their flights for free.

Phoenix has only hit highs of this level a handful of times in recorded history since 1896.

Temperatures are expected to creep up later on this week, and may even meet the city’s all-time high of 50 degrees, which was set on June 26 1990.